.\" $OpenBSD: SSL_get_peer_certificate.3,v 1.5 2020/09/17 08:04:22 schwarze Exp $
.\" full merge up to: OpenSSL b97fdb57 Nov 11 09:33:09 2016 +0100
.\"
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.Dd $Mdocdate: September 17 2020 $
.Dt SSL_GET_PEER_CERTIFICATE 3
.Os
.Sh NAME
.Nm SSL_get_peer_certificate
.Nd get the X509 certificate of the peer
.Sh SYNOPSIS
.In openssl/ssl.h
.Ft X509 *
.Fn SSL_get_peer_certificate "const SSL *ssl"
.Sh DESCRIPTION
.Fn SSL_get_peer_certificate
returns a pointer to the X509 certificate the peer presented.
If the peer did not present a certificate,
.Dv NULL
is returned.
.Pp
Due to the protocol definition, a TLS/SSL server will always send a
certificate, if present.
A client will only send a certificate when explicitly requested to do so by the
server (see
.Xr SSL_CTX_set_verify 3 ) .
If an anonymous cipher is used, no certificates are sent.
.Pp
That a certificate is returned does not indicate information about the
verification state.
Use
.Xr SSL_get_verify_result 3
to check the verification state.
.Pp
The reference count of the
.Vt X509
object is incremented by one, so that it will not be destroyed when the session
containing the peer certificate is freed.
The
.Vt X509
object must be explicitly freed using
.Xr X509_free 3 .
.Sh RETURN VALUES
The following return values can occur:
.Bl -tag -width Ds
.It Dv NULL
No certificate was presented by the peer or no connection was established.
.It Pointer to an X509 certificate
The return value points to the certificate presented by the peer.
.El
.Sh SEE ALSO
.Xr ssl 3 ,
.Xr SSL_CTX_set_verify 3 ,
.Xr SSL_get_verify_result 3 ,
.Xr SSL_get0_peername 3
.Sh HISTORY
.Fn SSL_get_peer_certificate
appeared in SSLeay 0.4 or earlier and has been available since
.Ox 2.4 .
